What bedding should I use?

[Giggitoni]

I have a GB that has a PVC piano hinge on the center windshield (for opening). The hinges only last for several years before breaking and needing replacement. Mine is there. What should I use to bed the new hinge? Silicone is not allowed on the boat! Sikiflex, ???

 

[Nomad Willy]

Yes,
SikaFlex bedding compound .. I think it’s 391.
Or you could use 3-M 4200. I haven’t used that but it’s reported to be UV resistant.
I have SikaFlex bedding compound all over My boat and no UV issues that I know of.

Ray, why don’t you get SS hinges?

 

[Giggitoni]

Thanks, Eric. GB has always used a plastic hinge. I drill my own holes in the PVC hinge in the exact spot to match the holes in the house. I wouldn't be lucky enough to have the holes match in a ss hinge.

Thanks, again.

 

[OldDan1943]

Thanks, Eric. GB has always used a plastic hinge. I drill my own holes in the PVC hinge in the exact spot to match the holes in the house. I wouldn't be lucky enough to have the holes match in a ss hinge.

Thanks, again.

Perhaps GB used plastic because it cost less?
Personally, I would check out the hole spacing on the SS hinges before I said, "Wont work".
Good luck.

 

[kchace]

Be careful what sealant you use, some are not compatible with plastic.

Ken

 

[Portage_Bay]

Thanks, Eric. GB has always used a plastic hinge. I drill my own holes in the PVC hinge in the exact spot to match the holes in the house. I wouldn't be lucky enough to have the holes match in a ss hinge.

Thanks, again.

If the SS hinge holes are far enough off from the GB original hinge holes just drill new and fill the old. If they overlap fill the holes with epoxy and drill again. As the best boat mechanic, ship wright, general all around boaty things guy I know asks.... "What could POSSIBLY go wrong?"

 

[RT Firefly]

Greetings,
Mr. G. Yup. Replace the plastic with SS. Fill the old mounting holes with a suitable material (thickened epoxy?) and be done with the bi-annual replacement OR buy undrilled piano hinges and match your current hole spacing. I would bed with either Dolphinite or butyl tape.


https://www.mcmaster.com/stainless-steel-piano-hinges/

 

[Mike GB32]

FWIW- I just refurbished that window on my '74 GB 32. It has SS hinges with what looks like a strip of canvas between the hinge and the house. I used Dolphinite in the screw holes only.
No leaks

 

[stubones99]

You can order stainless steel 316L hinges without holes. Then use the old one to drill the holes in the stainless hinges to match the boat. Perhaps macmaster carr?

They have all sorts... including titanium, plastic, aluminum, stainless,etc.

or here is one from another vendor
https://www.hingeoutlet.com/products/piano-hinges-stainless-steel-continuous-1-1-2-x-96

 

[Bacchus]

If you already have the plastic hinge and want to try it you might consider "wrapping" sunbrella or vinyl around the hinge so it gets captured between the window and frame. This not only improves water proofing but will shield it from UV that is likely contributing to the failure.

 

[wkearney99]

Anyone got a picture of this? I'm having a hard time imagining the use of PVC for a window hinge.

 

[Giggitoni]

Bill, I’ll take some picks during the fix and post them here. Hopefully this weekend.

 

[Comodave]

For general caulking I use Sika 291. For plexiglass or lexan type caulking I use Sika 295UV. For deck fittings and things that can be torqued down I use butyl tape. I used to use 3M products but since I tried the Sika stuff, I will not use the 3M except 5200 for thru hulls.